开放体系下平凉组页岩干酪根的生烃动力学研究  

Kinetics of hydrocarbon generation in open system of kerogen in the Pingliang Shale,Ordos Basin

作　　者：江林香[1,2] 王庆涛[1,2] 卢鸿[1] 刘金钟[1] 彭平安[1] 

机构地区：[1]中国科学院广州地球化学研究所有机地球化学国家重点实验室,广东广州510640 [2]中国科学院研究生院,北京100049

出　　处：《地球化学》2012年第2期139-146,共8页Geochimica

基　　金：国家重点基础研究发展计划(2012CB214706);国家科技重大专项(2011ZX05008-002-33);国家自然科学基金(40873048;41173053)

摘　　要：对鄂尔多斯盆地奥陶系平凉组海相页岩进行了3种升温速率下的Rock—Eval热解模拟实验，研究了其干酪根在开放体系下的热解生烃演化特征。通过分析热解烃S2的产率随温度的变化，结合Kinetics生烃动力学专用软件计算，获得了其开放体系下的生油动力学参数，活化能分布范围为（57～81）×4185kJ／mol。在此基础上进行的动力学模拟结果与实验数据非常吻合，可较好地将实验数据外推到地质实际过程。此外，发现热解残渣中的H／C（原子比）值与热解温度、干酪根转化率有较好的相关关系，可建立H／C值与转化率或者等效镜质组反射率的可靠模板，表明Rock—Eval热解实验与H／C值结合，可快速评价下古生界源岩的成熟度、转化率和生烃量等指标，将其应用于资源量计算等方面。The hydrocarbon generation characteristics of marine shale kerogen from the Middle ~rdovician Ping-Liang Formation were studied in this paper by simulation experiments based on Rock-Eval pyrolysis at three different heating rates. Combined with the patent software （Kinetics）, variation in the yield of thermally generated hydrocarbon （S2） with pyrolysis temperature was used to calculate the kinetic parameters of petroleum generation in open system. The calculated activation energies are in the range of （57-81）×4.185 kJ/mol. The result of kinetic simulation is in agreement with the experimental data, indicating that experimental results can be extrapolated to actual geological process. In addition, H/C atomic ratios of the pyrolysis residues show good correlations with pyrolysis temperature, kerogen conversion, and thermal maturity. Therefore, source rock parameters, such as thermal maturity, hydrocarbon conversion rate, and hydrocarbon generated amount, can be quickly evaluated by the combination of Rock-Eval pyrolysis and H/C ratio determination of kerogen.

关 键 词：海相页岩 Rock—Eval 开放体系 生烃动力学 H C值 

分 类 号：P593[天文地球—地球化学]